Dobbin played in two overseas tours and was the vice-captain to Paul Millar's 1912 team.

Dobbin was first selected for the national rugby team in 1903, in the First Test of the 1903 British Isles tour of South Africa.

South Africa had a poor international record to date, having played seven matches, all against the British Isles, and had won only one game.

Dobbin was brought into the South African team for the First Test, partnered at half-back with seasoned international Jackie Powell.

Dobbin celebrated his first cap by scoring one of the two South African tries, converted by Fairy Heatlie.